<div dir="ltr"><div class="gmail_extra"><div class="gmail_quote">On 21 January 2015 at 14:45, Matthew Flatt <span dir="ltr"><<a href="mailto:mflatt@cs.utah.edu" target="_blank">mflatt@cs.utah.edu</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">You're right that the essential problem is that `with-steps` introduces<br>
binding no-hygienically. Non-hygienic macros don't compose nicely.<br>
<br>
If `with-steps` were written in modern Racket, then it would be<br>
hygienic, where `vonly`, etc., are bindings that take their meaning<br>
as syntax parameters from an enclosing `with-steps`. Fortunately, it's<br>
possible to implement a more modern `with-steps` using the existing one.<br>
<br>
Use the enclosed "new-step.rkt" in place of `slideshow/step`, and then<br>
your `correct` macro will work.<br>
</blockquote></div><br><div class="gmail_default" style="font-size:small">​Thanks very much, works a treat!<br clear="all"></div><br>-- <br><div class="gmail_signature"><a href="http://rrt.sc3d.org">http://rrt.sc3d.org</a></div>
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